An acid-responsive all-in-one signal amplification strategy for the ultrasensitive prostate-specific antigen detection

Abstract

The prostate-specific antigen (PSA) is an important biochemical biomarker for the early screening and auxiliary diagnosis of prostate cancer. Hence, developing a simple and rapid method for the sensitive detection of PSA is crucial. Herein, all-in-one signal tags were successfully prepared via a one-pot coprecipitation strategy using ZIF-8 nanoparticles as nanocarriers, methyl yellow (MY) as signal molecules, and the antibodies of PSA as signal recognition units. After treatment with an acid solution, the signal tags (named ZIF-8/MY/Ab₂) would hydrolyze and release large amounts of MY molecules to induce an obvious colorimetric signal at 510 nm, which could quantificationally reflect the concentration of PSA. Furthermore, the colorimetric immunosensor exhibited satisfactory specificity, sensitivity, and reproducibility as well as practical feasibility in human serum analysis, which paves a new path for the early diagnosis of prostate cancer.